Sea Otters, Trophic Cascades, and Gentrification

John Muir claimed, “When we try to pick out anything by itself, we find it hitched to everything else in the Universe.”[1] I find evidence for Muir’s statement in what is called a “trophic cascade.” What is a trophic cascade? Encyclopædia Britannica defines a “trophic cascade” as follows: a “trophic cascade” is “an ecological phenomenon triggered by the addition or removal of top predators and” involves “reciprocal changes in the relative populations of predator and prey through a food chain, which often results in dramatic changes in ecosystem structure and nutrient cycling.” What are some examples of trophic cascades? The destruction and reduction of sea otters, wolves and whales are examples; their removal and reintroduction bring about dramatic changes in ecosystems and related natural phenomena.

The near extinction of sea otters in Monterey Bay as a result of hunting in the nineteenth century impacted negatively the ocean’s ecosystem. As a result, the kelp forests disappeared, since the sea otters were no longer feeding on sea urchins, which devoured the kelp (See these clips: “The Impact of Sea Otters”; “Trophic Cascade – Otters, Urchins, Kelp”). The reemergence of sea otters in the region has given rise to the return of kelp forests, which function as important nursery homes for young fish.

The reintroduction of wolves into Yellowstone National Park changed the ecosystem as well as the behavior or direction of rivers.[2] Wolves not only decreased the overwhelming number of deer and kept them from areas where they had decreased vegetation; their reintroduction also led to the regeneration of plant life in places like valleys and gorges; birds migrated into these regions, as did beavers, otters, rabbits, eagles, bears, and other forms of wild life. Regenerated forests reduced erosion along banks, decreasing meandering, making the rivers more stable in their course. The reduction in erosion benefited the wild life habitats. See this video titled “How Wolves Change Rivers.”

Whales change climate. Contrary to the belief that killing whales increases fish populations, the video “How Whales Change Climate” claims that whales increase fish populations and lead to the decrease in carbon as a result of nutrients and plankton associated with whale excrement, which is rich in iron and nitrogen, and whale movement in the water. The reintroduction of whales could be a beneficial form of geo-engineering that increase fish populations and the atmosphere.

If this is true of nature, perhaps it is true of human life as well. After all, humans are not separate from their natural habitats. So, what happens when various forces combine to remove people groups from their long-standing places of residence? Here I call to mind gentrification, which is often the result of urban renewal and resettling of middle class and upper class (gentry) people in those “revitalized” neighborhoods.[3] Does gentrification function as a human version of “trophic cascades”?

Now some might argue that gentrification operates differently than trophic cascades; after all, gentrification often pushes out what many take to be weaker (the less economically fit) people groups whereas trophic cascades, when negatively framed, push out the strong, as in the displacement of sea otters, wolves, and whales. No doubt, those with bigger paychecks and buying capital have a certain kind of prowess at the top of the food chain. So, I understand how some might take the middle class and gentry to be stronger and more resilient subcultures than those economically challenged people groups they displace.

However, contrary to this perspective, their economic prowess does not account for their impotence in caring for the entire environment. As in the case of those who hunted sea otters to near extinction for their pelts, those who hunt for cheaper properties at the expense of African American communities devastate rich cultural habitats. I have often found that the strongest and richest people are those who have gone through great travail, such as the African American community, in contending for the right to exist within systems that cater to the affluent and powerful. Where would America be without Black Gospel, Jazz, or the Blues, for example? (Take to heart the strength of soul in a context of duress and distress in the song played by Buddy Guy—“First Time I Met the Blues,” which you can view and listen to here.)

When neighborhoods lose their historic populations in favor of upwardly mobile homogeneity, they often lose their soul, which hitches a ride out of town with the displaced. After all, whether we are immediately aware of it or not, “when we try to pick out anything by itself,”—including a neighborhood’s historic community, we find it hitched to everything else in the Universe,” including that neighborhood’s spirit and even its nation’s soul.